The present invention relates to an apparatus for automatically filling a container with a post-mix carbonated beverage. More specifically, the present invention relates to an ultrasonic level detector for automatically controlling the filling of a container with a carbonated beverage which tends to form a head of foam thereon during the filling operation.
Heretofore, attempts have been made to provide apparatus which automatically fill beverage containers such as cups in response to the proper positioning of a cup under a beverage dispenser and then terminate the dispensing operation when a proper liquid level within the cup is achieved. The liquid level detector devices in these prior are systems generally utilize electrical probes such as conductive or capacitive probes to determine liquid level.
There are also known systems for measuring liquid level within containers utilizing ultrasonic transducers and associated detector circuitry. However, none of these appear to have been implemented for controlling the automatic filling operation of carbonated beverage cups.
The use of ultrasound has definite potential advantages for the purposes of controlling an automatic filling operation of beverage cups in that the ultrasonic transducer may be utilized both for initiating the filling operation in response to detecting the presence of a cup and continuously monitoring the liquid level within the cup during the filling operation until a predetermined liquid level is achieved. Both of these functions can be achieved by mounting an ultrasonic transducer adjacent to a dispensing nozzle of the post-mix beverage dispenser without cluttering the area of the dispensing machine adjacent to the working area where the cup is to be disposed.